CVE-2025-53845 in FortiAnalyzer
Summary
by MITRE • 10/14/2025
An improper authentication vulnerability [CWE-287] in Fortinet FortiAnalyzer version 7.6.0 through 7.6.3 and before 7.4.6 allows an unauthenticated attacker to obtain information pertaining to the device's health and status, or cause a denial of service via crafted OFTP requests.
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Analysis
by VulDB Data Team • 10/17/2025
The vulnerability identified as CVE-2025-53845 represents a critical improper authentication flaw classified under CWE-287 that affects Fortinet FortiAnalyzer devices running specific firmware versions. This weakness enables unauthenticated attackers to gain unauthorized access to sensitive system information and potentially disrupt service availability through carefully crafted OFTP (Fortinet Open File Transfer Protocol) requests. The affected versions span from FortiAnalyzer 7.6.0 through 7.6.3, while the vulnerability remains unpatched in versions prior to 7.4.6, creating a significant security gap that could be exploited by malicious actors.
The technical implementation of this vulnerability stems from insufficient authentication mechanisms within the OFTP protocol handler of the FortiAnalyzer device. When processing crafted OFTP requests, the system fails to properly validate the authenticity of incoming connections, allowing attackers to bypass the standard authentication procedures. This improper authentication mechanism creates a pathway for information disclosure where attackers can retrieve device health metrics, system status information, and potentially sensitive operational data that should only be accessible to authorized administrators. The flaw specifically manifests during the processing of OFTP requests, which are typically used for secure file transfers and system communications within Fortinet's security ecosystem.
The operational impact of this vulnerability extends beyond simple information disclosure to include potential denial of service conditions that could severely impact network security operations. Attackers exploiting this weakness can cause service disruption by sending malformed OFTP requests that may crash system processes or consume excessive resources, leading to availability issues for legitimate users. The device health information that becomes accessible includes system performance metrics, configuration details, and operational status that could provide attackers with valuable intelligence for planning more sophisticated attacks. This information disclosure capability aligns with ATT&CK technique T1082 (System Information Discovery) and T1592 (Gather Victim Host Information) as attackers can map the target environment without proper authorization.
Organizations utilizing affected FortiAnalyzer versions face significant risk exposure given the nature of the vulnerability. The unauthenticated access capability means that attackers can exploit this weakness from any network location without requiring valid credentials, making it particularly dangerous in environments where network segmentation may not be fully implemented. The vulnerability's presence in multiple versions within the 7.6.x release series indicates a systemic issue in the authentication implementation that could affect numerous deployments across different organizational environments. Security teams should consider this vulnerability as a high-priority threat that could enable reconnaissance activities leading to further compromise of the network security infrastructure.
The recommended mitigation strategy involves immediate deployment of Fortinet's security patches and firmware updates that address the authentication weakness in the OFTP protocol handler. Organizations should also implement network segmentation and access controls to limit exposure of FortiAnalyzer devices to untrusted networks while monitoring for suspicious OFTP traffic patterns. Network administrators should consider implementing intrusion detection systems with signatures specific to this vulnerability and establish monitoring procedures for unusual device status queries. The mitigation approach should align with NIST SP 800-53 security controls related to access control and system monitoring to ensure comprehensive protection against exploitation attempts. Additionally, security teams should conduct vulnerability assessments to identify any other systems that may be similarly affected by improper authentication mechanisms and implement compensating controls to reduce the attack surface.